/**
 *  Copyright (c) 1997-2013, www.tinygroup.org (luo_guo@icloud.com).
 *
 *  Licensed under the GPL, Version 3.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *       http://www.gnu.org/licenses/gpl.html
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.tinygroup.tinyscript.expression.operator;

import org.tinygroup.tinyscript.ScriptContext;
import org.tinygroup.tinyscript.ScriptException;
import org.tinygroup.tinyscript.assignvalue.AssignValueUtil;
import org.tinygroup.tinyscript.expression.ExpressionUtil;
import org.tinygroup.tinyscript.expression.OperatorWithContext;

/**
 * Created by luoguo on 2014/6/8.
 */
public class LeftSubtractSubtractOperator implements OperatorWithContext {

    public String getOperation() {
        return "l--";
    }

    //返回新值
	public Object operation(ScriptContext context, String name, Object value)
			throws ScriptException {
		Object newValue = ExpressionUtil.executeOperation("-",value,1);
		try {
			AssignValueUtil.operate(name, newValue, context);
		} catch (Exception e) {
			throw new ScriptException(e);
		} //执行赋值操作
		return newValue;
	}

}
